Overrunning or freewheeling clutches have developed over the years utilizing one or more inexpensive metal coil springs as an active clutching element and drive member between a shaft and a concentrically mounted cylindrical bushing, or between axially aligned shafts with the coil spring concentrically surrounding abutting portions of the aligned shafts. Particularly where one of the shaft and concentric bushings is the driving member, and the other a driven member, the coil spring is interposed concentrically between the two members, is affixed at one end to one of the members and, depending upon the direction of rotation of the driven shaft, frictionally engages the surface of the other driven member to drive the driven member in the same direction of rotation. Drive is disconnected by overrunning as a result of excessive speed of the driven member. Such action is accomplished by radial expansion of the coil spring. With the coil spring concentrically surrounding the shaft and interposed between the shaft and inner periphery of the outer concentric cylindrical bushing, sometimes during disconnect or overrunning action, the spring jams between the shaft and bushing with a non-release of the clutching action in spite of desired free-running.
U.S. Patents which are exemplary of such spring coil overrunning clutches are U.S. Pat. Nos.: 3,228,497 issued Jan. 11, 1966; 3,327,825 issued June 27, 1967; 2,785,587 issued Mar. 19, 1957; and 3,698,523 issued Oct. 17, 1972.
It is therefore a primary object of the invention to provide an overrunning clutch using a metal coil spring interposed between a shaft and a concentrically mounted cylindrical bushing of slightly larger diameter, in which the positioning and mounting of the spring to the cylindrical bushing is easily accomplished, positively maintained irrespective of whether the clutch is in active clutch or declutched condition, wherein the spring cannot be inadvertently disconnected from the bushing during clutch operation or termination of clutching and which prevents the inadvertent jamming of the coil spring between the shaft and bushing and non-release of the clutch under desired free-running conditions.